Obesity is a major modifiable risk factor for cardiovascular disease, and weight loss is associated with improvements in cardiovascular health, including cholesterol levels.1 However, many patients experience weight cycling (substantial weight loss followed by regain), which might impact cardiovascular health.2 While previous research highlights the benefits of sustained weight loss, less is known about the lipid profiles of individuals who regain lost weight.
To understand the effects of weight cycling, we studied 156,096 adult patients with an obese BMI who had at least three BMI measurements over an 18-month period that demonstrated specific patterns in weight change. Patients were categorized into three weight patterns: sustained loss (≥10% reduction that was not regained), steady (weight remained within ±2% of baseline throughout), and regain (initial ≥10% reduction followed by return near baseline). LDL values were compared from baseline result around the time of their first qualifying BMI to an LDL result around the third BMI measurement. Patients were matched based on age, sex, BMI classification, social vulnerability, comorbidities, and use of lipid-lowering medications.
We found that the average change in LDL differed by weight pattern. Patients in the sustained loss group had the largest average reduction, with LDL levels decreasing by 6.2 mg/dL. This contrasts with only a 1.9 mg/dL reduction in the regain group, despite similar initial weight loss, suggesting that cholesterol benefits attenuate quickly when weight is regained. Patients who maintained steady weight experienced a modest average decline of 2.7 mg/dL. The average LDL for all groups decreased, including those with stable weight, which might reflect underlying characteristics of the study population, such as increased likelihood of lipid management among those with repeat LDL testing. However, even within this potentially health-engaged subgroup, the gradient of LDL improvement across weight patterns suggests that the observed differences remain clinically meaningful.
The distribution of LDL changes further contextualizes these average effects. Patients in the sustained loss group were more likely to experience large reductions in LDL, with a greater proportion achieving improvements of 10 mg/dL or more compared to the other groups: 41% of the loss group had LDL reductions of at least 10 mg/dL, compared to 33% in the steady group and 34% in the regain group. Patients in the regain group had a greater proportion experiencing LDL increases. Approximately 32% of regain patients had LDL increases of 10 mg/dL or more, compared to 29% of the steady group and 27% of the loss group. Previous research has shown that weight loss can lead to transient increases in LDL levels, which might be a factor contributing to the LDL increase among the sustained weight loss group.3,4
